Goldbreast Splitfin
Ilyodon furcidens
A livebearer with a quasi-placenta and fork-shaped teeth. Genuinely unlike most aquarium fish.
About
The Goldbreast Splitfin (Ilyodon furcidens) is a goodeid livebearer from the Ameca-Magdalena and Armeria-Coahuayana river systems of western Mexico, and it's one of those fish that rewards a closer look. The species name references its unusual forked teeth, and mature individuals can develop a noticeable hump behind the head. Males and females are closer in size than in most livebearers, which is thought to be tied to how goodeid reproduction works. Partners need to be well-matched physically for mating to succeed. Unlike most livebearers, females cannot store sperm, so each brood requires a fresh pairing. The developing young are nourished through a structure called the trophotaenia, which functions much like a mammalian placenta, and the remnants of this are sometimes visible on newborn fry as a small cord-like attachment that disappears within a few days. Fry arrive large and confident, ready to compete for food alongside adults from day one. In the aquarium, these are peaceful fish overall, though males can be mildly pushy with one another without causing real harm. They suit a community setup with compatible tankmates and do best when given plenty of plant cover. An intermediate-level keeper willing to learn the quirks of goodeid reproduction will find them genuinely rewarding.
Similar species
Other fish you might consider
Good tank mates
Species that tend to coexist peacefully with Goldbreast Splitfin
From the same region
Share the same natural habitat. Great for a biotope-themed tank
Frequently asked questions
- How big does the Goldbreast Splitfin get?
- The Goldbreast Splitfin reaches about 1.5–4" as an adult.
- What size tank does the Goldbreast Splitfin need?
- A minimum of 7 gallons is recommended for the Goldbreast Splitfin.
- What water parameters does the Goldbreast Splitfin need?
- The Goldbreast Splitfin does best with a temperature of 75–82°F, a pH of 7–8, hardness around 10–20 dGH.
- Is the Goldbreast Splitfin aggressive?
- The Goldbreast Splitfin is generally peaceful and suits a community tank with similarly calm tankmates.
- What does the Goldbreast Splitfin eat?
- The Goldbreast Splitfin is an omnivore. It does well on a varied diet of quality flake or pellet plus occasional frozen or live foods.
- How long does the Goldbreast Splitfin live?
- With good care, the Goldbreast Splitfin typically lives 3-5 years.